Evaluation of Low Dose Silicon Carbide Temperature Monitors

Thermocouples are generally used to provide real-time temperature indications in instrumented tests performed at materials and test reactors. Melt wires or paint spots are often included in such tests as an independent technique of detecting peak temperatures incurred during irradiation. In addition, less expensive static capsule tests, which have no leads attached for real-time data transmission, often rely on melt wires and paint spots as a post-irradiation technique for peak temperature indication. Unfortunately, these techniques are limited in that they can only detect whether a single temperature is or is not exceeded. Silicon carbide (SiC) monitors are advantageous because a single monitor can be used to determine the peak temperature reached within a relatively broad range (200 – 800°C). Although the use of SiC monitors was proposed more than five decades ago, the ultimate performance limits of this technique are not fully understood. The Nuclear Science User Facilities (NSUF) is the United States Department of Energy Office of Nuclear Energy's only designated nuclear energy user facility. Its mission is to provide nuclear energy researchers access to world-class capabilities and to facilitate the advancement of nuclear science and technology. This mission is supported by providing access to state-of-the-art experimental irradiation testing, post irradiation examination facilities, and high performance computing capabilities as well as technical and scientific assistance for the design and execution of projects. As part of an NSUF project, low dose silicon carbide monitors were irradiated in the Belgian Reactor 2 and were then evaluated both at the SCK•CEN and at Idaho National Laboratory’s High Temperature Test Laboratory to determine their peak temperature achieved during irradiation. The technical significance of this work was that the monitors were irradiated to a dose that was significantly less than recommended in published literature. This paper will discuss the evaluation process, the irradiation test, and the performance of the low dose silicon carbide temperature monitors.

Comparative assessment of hypothalamic-pituitary-adrenal axis suppression secondary to intrabursal injection of different glucocorticoids: a pilot study

BACKGROUND

Hypothalamic-pituitary-adrenal axis (HPAA) suppression is the most common and dangerous, although often unrecognized and untreated, side effect of glucocorticoid administration. The risk and duration depend both on patient and treatment characteristics. High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) currently represents the gold standard method to evaluate the metabolism of endogenous and exogenous steroids.

OBJECTIVE

To assess prevalence, severity, and duration of HPAA suppression subsequent to the injection of two steroids with equivalent potency but different pharmacokinetics.

SUBJECTS AND METHODS

Single-blind randomized case-control pilot study. Forty patients (22 F; age 48.7 ± 7.2 years) with shoulder calcific tendinopathy received an intrabursal injection of 40 mg of 6α-methylprednisolone acetate (MA) or triamcinolone acetonide (TA). Just before (T0) and after 1 (T1), 7 (T2), 15 (T3), 30 (T4) and 45 (T5) days, we assessed morning blood cortisol and ACTH by RIA, and 24-h urinary levels of MA, TA and free cortisol by HPLC-MS/MS.

RESULTS

HPAA function was normal at baseline. At T1, all patients presented HPAA suppression reaching the lowest cortisol, ACTH and UFC levels, that were similar between groups. At T2, mean cortisol remained lower than at baseline (p < 0.0001) in the TA group. In both groups, mean cortisol and ACTH levels progressively normalized, suggesting HPA recovery, except for three patients in the MA and two in the TA group. UFC levels remained lower than normal (p < 0.0001) up to T5, despite the disappearance of exogenous GCs. No patient developed manifestations of hypocortisolism.

CONCLUSIONS

A single 40-mg intrabursal injection of MA or TA is sufficient to suppresses HPAA up to 45 days. Although typically asymptomatic, patients should be instructed to recognize and report symptoms suggestive for hypocortisolism, to provide prompt diagnosis, and eventually, treatment, thus avoiding severe complications.

Staging, Therapy and Prognosis of Primary Non-Hodgkin's Lymphoma of Bone and a Comparison of Results with Localized Ewing's Sarcoma: Ten Years Experience at the Istituto Ortopedico Rizzoli

Thirty consecutive cases of localized primary non-Hodgkin's lymphoma of bone (PNHLB) were treated in a 10-year period at the Istituto Ortopedico Rizzoli with localized radiation (4 cases) and localized radiation and adjuvant chemotherapy (26 cases). The doses of radiation varied from 3000-4500 rad. A variety of staging procedures evolving with new diagnostic techniques over the 10 years were performed. Adjuvant chemotherapy comprised two different regimens of vincristine, adriamycin and cyclophosphamide. Twenty-four of the 26 patients (92 %) have been free of disease with a median follow-up of 75.5 months (18-144 months). Two patients developed meningeal involvement and one patient, treated with radiation therapy only, developed a local recurrence. The results are compared to the management of 68 Ewing's sarcoma patients treated during the same period. Here, higher doses of localized radiation therapy (approximately 5000 rad) and similar adjuvant chemotherapy were administered. The survival was 32 % (22/68) with a higher incidence of local recurrence (21 %). These data indicate that PNHLB should be considered a separate entity from Ewing's sarcoma and can be treated successfully with lower doses of radiation to the primary tumor and adjuvant chemotherapy. The observations are also compared to a variety of other biological characteristics of Ewing's sarcoma. Since only two patients developed meningeal relapse, our experience does not permit a firm recommendation for routine prophylactic treatment of the central nervous system in PNHLB.

Solitary Plasmacytoma of the Vertebral Column. A Report of 15 Cases

The clinical features and the treatment results of 15 patients with solitary plasmacytoma of the spine observed in a 28-year period (1950–1977) are reported. The signs at presentation were back pain in 4 cases and spinal cord compression in 11 cases. Three of these patients had paraplegia. Radiologically, the alteration encountered was an osteolytic lesion in all cases. The local treatment was radiotherapy in 11 cases and surgery plus radiotherapy in 4 cases. In 3 patients systemic chemotherapy was also employed. Seven patients are alive without signs of disease 3 to 9 years (mean 6 years) after diagnosis. Eight patients developed multiple myeloma in a period ranging from 1 to 8 years (mean 3.5 years). The relationship between multiple myeloma and solitary plasmacytoma of the spine, as well as the best treatment for the latter, are discussed.

Autologous chondrocytes implantation: indications and results in the treatment of articular cartilage lesions of the knee

Articular cartilage lesions of the knee constitute a frequent event and one that is difficult to treat. In time, different surgical methods have been used with results that are often contradictory. The authors report the indications and results of different methods used in the treatment of cartilage lesions: in particular, the experience initiated in 1997 with autologous chondrocytes implantation is discussed. Between 1997 and 2000, a total of 40 patients were submitted to autologous chondrocytes implantation injected in suspension under a periosteal flap. This method includes wide exposure of the joint lesion by arthrotomy. Between 1999 and 2001, a total of 30 patients were submitted to autologous chondrocytes implantation using a tridimensional matrix. The availability of biomaterial simplified the implant method and made arthroscopy possible. All of the patients were submitted to serial clinical follow-ups. MRI was also conducted for a second arthroscopic look. The results obtained in both series after a mean follow-up of 4 years (range 2 to 6 years) are good, and confirm the effectiveness of the method that allows for complete morphological and structural repair of lesions of the joint cartilage.

Hip prosthesis revisions with LS stem: indications and results

The authors present a study that includes 350 patients affected with loosening of hip arthroplasty and submitted to revision with a Wagner LS stem at the 4th Division of the Rizzoli Orthopaedic Institute. Several different types of cotyle (Fitek, Wagner, Standard Cup, cemented cotyle with support ring, Octopus system) were used depending on the anatomopathologic findings, combined with autoplastic grafts. Staging and grading of loosening were based on the four G.I.R. grades. A clinical evaluation of results was based on the Merle D'Aubigné parameters modified by Charnley. For radiographic evaluation the De Lee Charnley areas were studied for cotyle, the Gruen areas for the femoral stem. Overall, good results were obtained in 175 patients, fair in 137, poor in 38.

Hip arthroplasty in coxarthrosis secondary to Paget's disease

A total of 5 hip arthroplasties implanted between 1997 and 2000 in 5 patients affected with coxarthrosis secondary to Paget's disease were reviewed. The quality of the pagetic bone (sclerotic and very vascularized) resulted in a slightly longer amount of time required for surgery because of the difficulty preparing prosthetic placement and intra- and postoperative blood loss exceeding the norm. Complications were not observed. Clinical results were good in 100% of cases. Radiographically, 2 stems were assembled in varus.

Survival analysis of transfused fetuses affected by Rh-alloimmunization

The aim of the present study was to evaluate the survival rate of a group of 86 fetuses affected by Rh-alloimmunization submitted to intrauterine red blood cell transfusion. All the women had antibody titres> or = 1:32 at the time of their enrollment in the study. Crude fetal survival rate was 89.5% (77/86 cases). Data were stratified according to specific cut-off points of (1) pre-transfusion fetal haemoglobin expressed as the rate between the observed and the estimated value for each gestational age at the time of the first transfusion; (2) the difference between the haemoglobin at the beginning of the second-transfusion less that at the end of the first transfusion (delta haemoglobin); and (3) presence of ultrasound detected anomalies. Statistically significant stratification of the survival rate was observed for the level of pre-transfusion fetal haemoglobin (95% and 76.9%, respectively, p= 0.009) using a cut-off value of < 70% and > or = 70% of the expected value. Again, delta haemoglobin showed a different survival rate when a cut-off value of 6 g/dl was used to generate subgroups of fetuses: 94.6% and 80%, respectively (p= 0.0145). Among the ultrasound anomalies, the presence of hydrops showed a correlation with the survival rates. The quoted values were 97.83% (absence) and 80.0% (presence) respectively (p= 0.0058). Cox regression showed a significant association of the studied variables with the outcome (survival). The presence of hydrops was the best predictor (Odds ratio= 8.7, p= 0.0073) followed by Delta haemoglobin (Odds ratio= 2.0, p= 0.0422). The rate of pre-treatment fetal haemoglobin < 70% of the expected value did not add any significant valu and was thus removed from the final model. Weight at delivery expressed in grams showed a direct correlation with the survival rate (Odds ratio= 0.9, p= 0.1529) and was added into the model as an adjustment quantitative variable.

Loss of bone mass after total hip replacement: preliminary data

In a total of 37 females with cemented total hip replacement for monolateral coxarthrosis, of which 13 with prosthetic stem loosening, and 11 with monolateral coxarthrosis that is not prosthetized, bone mineral density (BMD) is determined by dual ray photonic absorbimetry selecting regions of interest (ROI) on the cortex of the femurs 4 cm under the lesser trochanter and on the ischium bilaterally. In females that are not prosthetized there are differences in bone mass between the two femurs and the ischium on both sides. In prosthetized patients BMD of the femur and of the ischium on the side operated on is significantly less than on the contralateral one (Student's "t" test: p < 0.001). In patients with stable prostheses, BMD of the femur operated on is greater than that in females with prosthetic stem loosening (Student's "t" test: p < 0.000). Based on a comparison between these two groups we did not observe any other significant differences in BMD among the ROI analyzed. BMD was correlated with the amount of time since surgery only in the ROIs in prosthetized femurs. The study confirms the significant bone resorption of the cortex in prosthetized femurs and documents analogously significant reduction in BMD in the ischium on the side operated on. Finally, it indicates that prosthetic stem loosening may be associated with loss of BMD in the femoral cortex which is significantly greater than that observed, during analogous periods of time in stable implants.

Knee prosthesis in rheumatoid patients

Total knee arthroplasty is a reliable means to improve the quality of life not only in osteoarthritis, but also in rheumatoid patients. Specific aspects, like the low mechanical quality of bone tissue, the contemporary damage of several joints and the higher risk of complications, have to be taken into account in rheumatoid arthritis. The experience with 24 prostheses in 21 rheumatoid patients is reported and confirms the efficacy of this operation. Among the technical details discussed, stress is placed on the conservation of the posterior cruciate ligament, the use of cement, the procedure of patelloplasty instead of prosthetic replacement. Careful preoperative planning is required and resections, especially in the tibia, should be economical. The evaluation of the results according to the protocol of the America Knee Society shows a satisfactory increase both of the articular score (average from 36 to 88) and the functional score (average from 34 to 68).

The biological problems of total hip arthroplasty

Biological phenomena are the principal agents in triggering hip prosthesis aseptic loosening. The authors report the results of "in vivo" and "in vitro" and Raman-laser experimental tests, which confirm the validity of the ceramic-ceramic combination in relation to the amount of wear and biocompatibility of friction materials.

Ultrasound in the evaluation of bone fragility caused by osteoporosis: a comparison between different sites of measurement

The authors compare two different measurement sites of ultrasound transmission velocity (UTV) in discriminating between subjects with or without vertebral fracture caused by osteoporosis. To this purpose a total of 150 women in menopause, of which 50 with vertebral fracture documented radiologically, for whom UTV was measured in the distal radius and in the patella, were examined. In both sites measurement of UTV in fractured women (1531.9 m/sec in the distal radius, and 1825.1 m/sec in the patella) was significantly less than for healthy women (1557.4 m/sec in the distal radius and 1874.5 m/sec in the patella) and there was a significant inverse linear correlation with age. The logistic regression shows that in both sites ultrasound examination is capable of significantly discriminating between osteoporotic women with fracture and those without fracture (odds ratio of the distal radius = 38.857, odds ratio of the patella = 7.822). A comparison of the discriminating capacity of the two measurement sites shows that the ORC curves for the distal radius (area = 0.773) is significantly greater than that of the patella (area = 0.684). Our study confirms that UTV can discriminate healthy subjects from osteoporotic ones, and it shows that the method in question has greater diagnostic sensitivity in the distal radius than in the patella.

Different gonadotropin and leuprorelin ovulation induction regimens markedly affect follicular fluid hormone levels and folliculogenesis

OBJECTIVES

To clarify the endocrine mechanisms underlying the outcome of different ovulation induction regimens with gonadotropins and GnRH agonists (GnRH-a).

DESIGN

Prospective study.

SETTING

Reproductive Endocrinology Center, University of Bologna.

PATIENTS

Forty eumenorrheic women randomly assigned to four groups of 10 subjects each.

INTERVENTIONS

Ovulation induction regimens: group A, purified FSH only; group B, purified FSH and flare-up GnRH-a; group C, purified FSH and long GnRH-a; and group D, hMG and long GnRH-a.

MAIN OUTCOME MEASURES

Pelvic ultrasound and hormone levels in daily serum samples and in follicular fluid drawn immediately before hCG administration.

RESULTS

Exogenous gonadotropin dose did not differ among groups. Group B had fewer preovulatory follicles than group C. Group B had higher serum LH, FSH, E2, P, T, and follicular fluid LH, E2, T, and alpha-inhibin than groups C and/or D. Groups C and D did not differ.

CONCLUSIONS

Long GnRH-a regimens improved follicle yield and the endocrine milieu in spite of comparable exogenous gonadotropin dose and lower serum FSH and thus appear to be preferable in assisted reproduction. Reduced folliculogenesis found in flare-up GnRH-a regimens could be mediated by the atretic effects of high intraovarian androgens. Efficacy of purified FSH and hMG was comparable.

Recurrent posterior instability of the shoulder: surgical treatment

A total of 11 cases of posterior instability of the shoulder surgically treated by simple capsuloplasty or associated with reinforcement of the posterior wall by bone graft or muscle transposition were reviewed. Accurate selection and preoperative evaluation of the patient when choosing surgery is very important. For surgery to succeed prolonged postoperative immobilization and an intense rehabilitative program to be initiated prior to surgery are necessary. Generalized ligamentous hyperlaxity constitutes a negative factor in prognosis, so that it is important to associate capsuloplasty with posterior bone block, in an attempt to avoid the risk of recurrence as further surgery would have an unfavorable outcome.

Glomus tumor in children (description of one case)

Glomus tumor is a lesion of the soft tissues which rarely occurs in children. One case of the disease characterized by deep localization and atypical radiographic symptoms and manifestations is described.

Case report 590: Diffuse pigmented villonodular synovitis with a cartilaginous component

The authors present the case of a patient 54 years of age who developed well-defined osteolysis in the distal end of the humerus, with a slight radiodensity in the soft tissue. The radionuclide scintigram and above all the CT, were useful in defining the characteristics and expansion of the mass more precisely. Surgical intervention and histological examination demonstrated a seemingly unique case of PVNS of the elbow with diffuse cartilaginous components and erosion of the distal end of the humerus. The pathological findings in this unusual case, actually suggested the possibility of an intermediate form of PVNS associated with synovial chondromatosis.

A critical review of the surgical treatment of infantile fibrous dysplasia

A critical review of the surgical treatment of 65 cases of infantile fibrous dysplasia demonstrated that "circumscribed" forms of the disease generally do not require any type of surgical treatment, while "extended" forms, as well as Albright's syndrome, require early surgical treatment aimed at preventing the development of skeletal deformities which are difficult to correct. Prophylactic intramedullary nailing with nails of suitable calibre most effectively achieves this goal.

Brown tumor of the tibia as an early manifestation of renal osteodystrophy. A case report

A brown tumor of the tibia occurred in a 49-year-old woman on dialysis with chronic renal failure. This lesion was the first clinical or radiographic indication of bone involvement. Although serum levels of calcium and phosphorus are often well regulated by dialysis, clinical or radiologic evidence of a brown tumor may prove to be the first sign of renal osteodystrophy in patients with chronic renal failure.

Intravascular intrauterine transfusion for severe erythroblastosis fetalis using different techniques

Over a 3-year period, 44 ultrasound-guided intravascular transfusions were performed between 18 and 32 weeks on 15 patients with severe erythroblastosis fetalis due to Rh immunization. In 4 fetuses, the first transfusion was performed before 20 weeks, in 6 between 20 and 25 weeks and in the remaining 5 between 25 and 31 weeks. Eight of the 15 fetuses were hydropic at the time of referral. Five transfusions were done in the intrahepatic umbilical vein, 6 were simple transfusions via percutaneous umbilical cord puncture, and 33 were partial exchange. There were 4 intrauterine deaths before 26 weeks, despite successfully performed transfusions: 3 of these fetuses were severely hydropic, while in the remaining fetus hydrops had been reversed in utero. Following delivery by cesarean section at 32 weeks of gestation, 1 of the neonates developed respiratory distress syndrome and died 17 h after birth. The overall survival rate was 67% (10 of 15 cases): 4 of the 8 hydropic fetuses (50%) and 6 of the 7 nonhydropic fetuses (83%) were alive at birth and survived the perinatal period. Three of the 5 losses occurred among the first 4 cases, while in the last 11 cases the survival rate increased to 82% (9 of 11).

Benign fibrous histiocytoma of bone

The cases of seven patients who had a lytic lesion that was histologically similar to a metaphyseal fibrous defect (non-ossifying fibroma) of bone were studied. The patients all were adults and had pain without a fracture. These features were considered distinctive for the lesion, which has the same histological appearance as benign fibrous histiocytoma of soft tissue. The lesion is a benign tumor with fibroblastic and histiocytic differentiation. This picture may be seen in foci in other lesions of bone (aneurysmal bone cyst, fibrous dysplasia, and giant-cell tumor). Ten cases of giant-cell tumor of bone that had a large component of the same foci were also reviewed. It should be emphasized that these areas are secondary reactive tissue rather than the true neoplastic tissue of benign fibrous histiocytoma.

Sacral osteoid osteoma and osteoblastoma: a report of 13 cases

The authors present 13 cases (nine males and four females) of osteoid osteoma and osteoblastoma of the sacrum. All patients were less than 20 years old. Clinical and radiographic findings, histological features, and therapy of these rare lesions are discussed. Surgical excision with a posterior approach is considered the treatment of choice, except for tumors localized in the body of S-1, which require an anterior approach. The prognosis is good, even when the neoplasm has been incompletely removed. Nevertheless, a marginal or wide resection is the recommended surgical treatment. Radiotherapy is necessary only for inoperable tumors.

A randomized trial for the treatment of high-grade soft-tissue sarcomas of the extremities: preliminary observations

A new trial for evaluating the effectiveness of adjuvant chemotherapy in high-grade soft-tissue sarcomas of the extremities in adult patients is presented. All patients after local treatment were randomized into two arms, one without further therapy and the other to receive adjuvant chemotherapy (Adriamycin [Farmitalia-Carlo Erba, Milan, Italy], 450 mg/m2). The preliminary results of the study are reported at a median observation period of 27.6 months. Of the 59 patients who entered the study, 79.1% in the chemotherapy group are without sign of disease, whereas the corresponding figure in the nonadjuvant chemotherapy group is 54.3%. The difference between the two groups is statistically significant (P less than .005, log rank test). These preliminary observations encourage continuation of the study.

Aneurysmal bone cyst of the spine

The cases of twenty-two patients with an aneurysmal bone cyst of the spine above the sacrum were analyzed with regard to sex, age, site, symptoms, and radiographic findings. Four patients had extension of the lesion to the adjacent vertebra or rib, and twelve patients had neurological deficits. The primary treatment was either radiotherapy or surgery alone, or surgery and radiotherapy combined. No recurrences were found in patients who were treated with surgery alone or with surgery and radiotherapy, while three of the six patients who were treated with radiotherapy had a local recurrence, two of which were fatal. The patients with neurological deficits recovered after healing of the cyst.

Localized Ewing's sarcoma of bone: ten years' experience at the Istituto Ortopedico Rizzoli in 124 cases treated with multimodal therapy

The results obtained in the treatment by multimodal therapy (surgery, radiation therapy and chemotherapy) of 124 cases of Ewing's sarcoma are presented. At a medium follow-up of 65 months 48% of the patients are disease-free. One patient died of leukemia and two patients developed an irradiation-induced sarcoma. Analysing the data, three factors seem to be correlated to prognosis: location of the initial lesion outside the pelvis and sacrum, a four-drug chemotherapy protocol and the use of surgery in the treatment of the initial lesion seem to give better results.

Angiosarcoma in chronic osteomyelitis

The authors present 4 cases of angiosarcoma occurring in chronic osteomyelitis observed at the Tumour Centre of the Rizzoli Institute. The literature is reviewed.